Welcome to the Castle Lake Limnology Lab homepage. This site lists selected publications written about Castle Lake, describes the research and data conducted, and includes a detailed overview of the Castle Lake food web. There is also an extensive photo gallery which provides a more visual representation of the scenery and biota of the region.
This lake is well studied, and with its long-term dataset which dates back to 1959, Castle Lake is one of the best documented lakes in the world!
Limnology courses that are taught at the University of California (Davis) and the University of Nevada (Reno) use Castle Lake to illustrate (and demonstrate) and number of principles.
Please note that many of these presentations have embedded images, making the filesize fairly large (a few megabytes). You probably want to be on a fast Internet connection to download them.
Academic Quarter: Fall 2006
CRN: 44225
Course: GEO298
Location: Wickson 2120J
Meeting Time: Tuesdays 4:30 to 6:00 pm
Units:2
This course is designed as a review and discussion of trends in aquatic food-web research with an emphasis on a landscape level perspective on food-web structure and trophic dynamics. Specific areas of focus will include ecosystem connectivity, nutrient cycling and vectors, and aqua-terrestrial food-web subsidies. The goal of the course will be to design a monitoring approach for lake food-webs that incorporates these ideas and a watershed scale perspective on lake trophic dynamics. Attention will also be given to probable impacts of climatic change associated with global warming on aquatic-food webs.
Course requirements:
Periodically, Castle Lake will appear in the news. We try to provide links to those stories from this website. Additionally, we will relate the ongoing work and activities of the lake from this page, although these stories will initially appear on the homepage.
Tom Stienstra, who writes the Outdoors section of the San Francisco Chronicle, recently wrote an piece about the Mt Shasta vicinity, focusing on Castle Lake. Castle Lake is a great place for ice fishing, which the Limnology 151 class does each spring during the class fieldtrip.
The science done at the Limnology Lab it to help conserve the lakes pristine beauty, so it can continue to be featured as a prime destination for outdoor enthusiasts.
Mt. Shasta News – 12/5/07
By Paul Boerger, staff writer
Ecologist and researcher René Henery of UC Davis presented an overview of the Mt. Shasta region watershed last week, emphasizing the need for research on the headwaters area.
Henery's “mantra,” which he frequently repeated during the Nov. 28 talk at the Flying Lotus in Mount Shasta, was that to fully comprehend the headwaters complex relationship to the area and the use of the water elsewhere - such as the flows that go to more southern parts of California - researchers need to look at the broad interrelationships of the rivers, 14,162 foot Mt. Shasta and its glaciers, and habitats.
“This is a very special place with a wealth of natural resources,” Henery said. “These are natural resources essential to the State of California. Natural resources nobody knows much about. This is a system that is poorly understood.”
http://www.mtshastanews.com/articles/2007/12/05/news/area_news/02headwat...
The Castle Lake 50 Year Reunion made local news (the Mt. Shasta News), thanks to the pen of Paul Boerger, the local journalist present during the Saturday morning meeting. This article focuses on Dr. Goldman and his role in building the laboratory at Castle Lake.
"During last month's 50th anniversary celebration of that initial study, approximately 150 students, former students, colleagues and former colleagues of [Dr.] Goldman gathered for a weekend at the lake to renew their commitment to continuing the study and to reminisce about old times."
"In the modern ecology era, following decades of research, relationships between natural systems are taken for granted; but in the 1950s this was breakthrough research."
Please click on the following link for the full story:
http://www.mtshastanews.com/articles/2007/08/08/news/area_news/01goldman...
>> View Images from the Castle Lake 50 year Reunion.
To navigate to this album, first click on the "Photo Gallery" link to the right. Then click on "The Research Station" followed by "Castle Lake 50 Year Reunion".
Photos of the Castle Lake 50 Year Reunion are being collected on this site. If you have photos to add, please Contact Us and we'll provide the necessary instructions to add your images.
Ken Osborn: http://www.flickr.com/photos/misterken/sets/72157600976459663/
Dale Mead: http://www.flickr.com/photos/damead/sets/72157600976593433/
Christian Thomas: http://share.shutterfly.com/action/welcome?sid=0AZOWTFs1YsWLsw
Earl Byron: http://www.flickr.com/gp/10883455@N08/85u8L6
Please see the story on the Castle Lake Limnological Research Station on the College of Agricultural and Environmental Sciences (CA&ES) website: http://caes.ucdavis.edu/NewsEvents/News/WebNews/jun_castle.htm
Charles Goldman and John Stumbos worked closely with Michelle Immel, a student intern in our Communications Unit, to develop the story.
Dear Students, Friends, and Associates of Castle Lake, California:
Lend me your eyes! After nearly half a century of research, teaching and good times, we are having the Castle Lake 50 Year Reunion this summer at the lake on July 20, 21 and 22. Get it on your calendar now for I would hope to see most of you there. We will have a small seminar as a reminder of the Science and a major party with all the courses you remember from days of yore. The main reason is to recall the science that was done, with the comradely that Castle lake has always provided, and to help revitalize our research program as we enter a new and exciting phase of research. We will have time to tell the best stories from the past and enjoy seeing old friends from years that have flown past so fast since graduation. Jobs and marriages have now scattered us across the country and the world; it is important to get together while we are all still young enough to enjoy the memories and the outdoors. The Methodist camp has already been rented for logistic support so that your whole families can attend the reunion and camp out or stay in motel accommodations in Mt. Shasta City during the weekend. There will be both art and music a great string quartet playing on the new raft in the middle of the lake. Just imagine the fabulous acoustics that the cirque basin will create. See the energy efficient use of solar power and the lab much as you remember it. Over the years the food has gotten better and better as the chief chef has honed his skills.
Located 20 minutes outside the town of Mt. Shasta, on the shore of beautiful Castle Lake, in Northern California’s Siskiyou mountains, the Castle Lake Limnological Research Laboratory has been in operation for going on fifty years. In addition to data collection for the Castle Lake Long-Term Monitoring Program the Lab supports graduate and postgraduate researchers from the University of California Davis and the University of Nevada Reno. Responsibilities of summer research associates and interns include field work and physical and chemical data analyses for the long-term data set, assisting with graduate and post graduate research projects, upkeep and improvements to the facility, and hosting field trips and community focused educational events.
Interns and researchers at the Castle Lake Limnological laboratory typically operate on a regular eight hour a day work schedule though some variation can occur on sampling days. The summer field season typically begins June 20th and runs through September 20th and internships can be organized for all or portions of the summer field season.
The Castle Lake Limnological Research Station cordially invites you to the Summer 2007 Castle Lake Reunion at Castle Lake.
Because Castle Lake is now financially supported by both UCDavis and UNR, we want to celebrate this new era of research at Castle Lake!
Reserve this weekend on your calendar: July 20th, 21st, & 22nd, 2007
Suggested attire: shorts, tee-shirt, swimsuit
We plan to update update this announcement, providing links and phone numbers to places to stay, such as Bed and Breakfasts and local motels. Of course, you can aways camp by the lake, and we have reserved the Methodist Camp for the weekend also. Please contact us, providing your name, email address, and year's that you visited or worked at Castle Lake, so that we can keep you informed about this and future events.
Sudeep Chandra (and his dog Old Girl) made the headlines in Nevada News for their work on the Truckee River. Sudeep and his crew from the lab are studying the river extensively. They collect aquatic invertebrates, algae, and fish samples for nitrogen and carbon stable isotopes analysis; this will help them to understand the composition of the entire food web of the river.
"If we can manage the river better, it’s good for business, and our community. I really think we can bring people into Reno because of this river -- it helps make Reno a great place to live. Hopefully we can provide local and regional user groups and managers the information they need to make the river better. That’s our goal."
Link: Nevada News
The uplift of the Cascade Mountains, northwestern United States, is a result of plate tectonics. The Juan de Fuca oceanic plate collides with the North American continental plate forming a convergent plate boundary, creating a subduction zone. The denser oceanic plate descends under the continental plate, and the oceanic crust heats, melts, and forms magma underneath the earth's surface. The Cascade Mountains are a series of volcanoes ranging from Mt. Lassen (California) in the south up to Meager Mountain (British Columbia) in the north.
Castle Lake and the Limnological Research Laboratory is located southwest of Mt. Shasta City in the Shasta/Trinity National Forest of northern California.
Castle Lake was formed during the Pleistocene Era over 10,000 years ago when much of North America was covered with glaciers. A glacier carved out the basin in which Castle Lake lies today. Castle Lake is a typical glacier 'cirque' lake. Cirque is a French word meaning semicircle or amphitheater. Cirque lakes are the deepest against the steep rock wall--also known as the cirque face-- where the glacier did most of the eroding. The northeastern shore of the lake is a terminal moraine of boulders and gravel that form a natural dam.
The rock composition within the Castle Lake basin is generally very poor in the essential plant nutrients nitrogen and phosphorus, which partially explains the great clarity of Castle Lake and why it is only moderately productive.
Against the cirque face of Castle Lake, the waters are up to 110 feet deep (35 M). At the other end of the lake is the outlet where the lake's depth ranges from 10 to 15 feet (3 to 5 M).
The Castle Lake basin primarily contains dense mafic and ultramafic rocks that solidified from magma underneath the oceanic plate 400 to 500 million years ago. Usually, as dense oceanic plates move towards lighter continental plates, they sink and re-melt. Surprisingly, these oceanic rocks were moved on top of the continental plate and were preserved. Oceanic rocks that are thrust on top of continental rocks instead of subducted are called ophiolites. After the ophiolite was in place on the continent, magma intruded into these oceanic rocks 250 to 300 million years ago forming diorite and granodiorite plutons. These plutons are more resistant to erosion than the oceanic gabbros. This explains why the diorite and granodiorite rocks are found on the ridges surrounding the Castle Lake basin.
The following file is the geological layer exported for Google Earth. Click on the link below to launch Google Earth and automatically pan to Castle Lake with the geological layer overlaying the terrain. Click on the labels for a descriptions of the symbol, or scroll down toward the bottom of this page for more details.
The following are shape files (.shp) which can be brought into ArcGIS, QGIS, or other GIS system which can read this format. GIS Mapping of Castle Lake is a work in progress, and we hope to add and improve these files over time.
cal_lake : Lake Layer
cal_outflow : Stream Outflow
cal_geol : Geology Layer
cal_geom : Geomorphology Layer
cal_dikes : Dikes
cal_faults : Faults
Coordinate System / Projection
NAD83 California Teale Albers
Download Shapefiles
This GIS work was done by Brooke Eustis, with some assistance from Ryan Boynton and Dave Waetjen.
Mt. Shasta is a majestic mountain. It rises 14,179 ft. (4,322 meters) above sea level, and is the second tallest peak in the Cascade range (behind Rainier) and the fifth tallest in California.
Mt. Shasta is the said home of the ancient lemurians. For more information on this lore, visit the following website:
The Medicine Lake Shield volcano is located in the rain-shadow north-east-east of Mt. Shasta (Latitude: 41.58 N, Longitude: 121.57 W). While it is still considered part of the Cascade chain of volcanoes, most of the others are stratovolcanoes, having steeper slopes and a higher elevation. The region is filled with remnants of past eruptions, which include Lava Beds National Monument, Glass Mountain, numerous smaller cinder cones, and Medicine Lake itself, from which Medicine Lake volcano derives its name.
The Medicine Lake shield volcano is the largest volume volcano in the Cascade range (Ritter and Evans, 1997). This is a bit surprising since it practically sits in the shadow of Mt. Shasta and is significantly smaller in elevation; Mt. Shasta is 4,317 meters above sea level while the Medicine Lake shield volcano is only 2,412 meters. But the Medicine Lake shield volcano has broad, gentle slopes built from the eruption of basalt that flows easily across the ground while Mt. Shasta is a stratovolcano, also called a composite volcano, formed by alternating layers of pyroclastics and lava that have accumulated over thousands of years to form a tall cone. The total area of the flows from the Medicine Lake shield volcano is much greater than those of the stratovolcanoes of the Cascade range, including Mt. Shasta.
Lava flows from the Medicine Lake volcano cover an area of approximately 2000 km2, approximately 40 km east to west and 50 north to south (Ritter and Evans, 1997). The flows are approximately one kilometer thick. The flows are composed chiefly of rhyolitic, basaltic, basaltic andesitic, and andisitic rock.
Most eruptions initially occurred during the Pleistocene (1.8 million years ago to 10,000 years ago) and later in the the Holocene (10,000 years ago to present) with the most recent eruptions, forming Glass Mountain, occurring approximately 1000 years ago (Ritter and Evans, 1997). The volcano rests on top of a Tertiary and early Quaternary volcanic plateau (Condie and Hayslip, 1974).
Looking at a geologic map of the region, one can see the vast flows emanating from the caldera rim, made up of the chief compounds described above. The most notable features when looking at the region are the 100+ Quaternary and Pliocene cinder cones that formed in the region. A cinder cone is a steep sided volcano (sometimes 40 degrees) and usually not more than a few 100 ft high. These cinder cones were formed from pyroclastics (rock fragments or congealed lava) spewed from a single vent in the earth. The fragments fall around the base of the vent, forming the cone shaped mound. Many of these cinder cones are now covered in vegetation, but the shape and size provide a clue to their identity.
Medicine Lake sits in the caldera, the depression near the eruption site. The lakes has an area of 1.65 square kilometers, a volume of 10,860 acre feet, a maximum depth of 46 meters and a median depth of 5 meters. The lake bed is composed of relatively course rhyolitic material producing a high pitch scraping sound when trampled.
The rim of the caldera is roughly 7 x 12 kilometers. It is speculated that no single eruption caused the formation of the caldera, but rather it collapsed as a result of a series of lava extrusions early in the volcano's history.
The lake has cultural significance to several Native American tribes. For example, the Pit River people believe the Creator's spirit is in the lake, providing powers to heal and renew oneself. For this reason, the area has been a training ground for medicine men. Although it has been designated as a Traditional Cultural District, this is being threatened by the construction of a geothermal plant that is to be constructed one mile from the lake, an initiative approved by the Bush administration.
The eruption that created Little Glass Mountain occurred less than 1000 years ago, just west of the caldera rim of the Medicine Lake shield volcano. The flows are composed mainly of rhyolite and dacite, which include extremely large obsidian, pumice, and olivine boulders. Many of the olivine specimens have many pore spaces that are produced by gasses that escape as the lava cools. Obsidian has a a glassy texture, and it has cooled quickly preventing the formation of crystals. Pumice, an ultra light porous glass which can sometimes float in water (Wyckoff, 1999).
Because of the composition of rocks in the area, one needs to be careful while hiking around this flow. Obsidian can be very sharp. One slip could quite easily produce a knife like cut. Because of this property, obsidian is one of the main rock types used by Native Americans in the creation of arrow heads and stone tools. Little Glass Mountain is a rich source of obsidian, and it was likely exploited by many groups in the region.
The Lava Beds National Monument is located on the north eastern flank of the Medicine Lake volcano. Like most of the other flows of the region, the lava compounds are mostly basaltic and andesitic. In addition to the cinder cones (described above), the region also boasts spatter cones and maar volcanoes. Spatter cones erupt through minor vents where the ejected materials fly through the air and solidify before hitting the ground, forming "clinkery" rocks. Maar volcanoes are eruptions that form flat bottom craters and are without a cone (Wyckoff, 1999).
According to the National Parks Service, there are over 500 lava tubes. Non-claustrophobic visitors to this national monument can explore these tunnels, some of which go for more than a mile under the earth. A light source is essential, and two backup light sources are recommended. While these tubes have their share of lava-based stalactites, most are smooth surfaced.
The semi-arid desert environment of Lava Beds receives an annual average rainfall of 15 inches. Because of the relatively high altitude, the winters are cold, and the average annual snowfall is 44 inches. The area supports are high diversity of desert plant life, including desert sage (Salvia dorrii carnosa) and desert sweet (Chamaebatiaria millefolium). Fern species are present at the entrances to some of the the caves including the spreading wood fern (Dryopteris expansa) and the western swordfern (Polystichum munitum).
Official Website: http://www.nps.gov/labe/
Food webs are a conceptual organization of different life forms that shows the flow of energy (as food) from one group to another. Food webs describe how each life form is inherently related/connected in a given ecosystem. A simplified food web is described below for Castle Lake.
A food web describes a cycle of energy and material flow so the beginning point is arbitrary. Using sunlight, CO2 and other available nutrients, algae grows and reproduces their biomass. The amount of algal growth determines the majority of the new biomass production in the food web, thus algae are usually referred to as at the base of the foodweb. Different types of zooplankton eat algae, and grow in number and size. In turn, fish prey on zooplankton and other benthic invertebrates (including insect larve). Ospreys, which eat fish, are the so-called top predators (excluding humans) at Castle Lake. All animals excrete CO2 and feces, which contain nitrogen (NH4), phosphorus, and other nutrients that are essential for algal growth. All dead life forms are decomposed by a rich variety of microbes. Decomposition releases a significant amounts of nutrients into the water as well.
Fish were introduced into Castle Lake, as with many surrounding lakes, in the 1930's for recreation fishing. Previously Castle was a fishless lake and the ecosystem consisted of algae, zooplankton, aquatic insects, and probably frogs.
This diagram will be improved in the future.
| BASIN DATA | |
| Surface elevation: | 1,657 m (5435 ft) |
| Lake surface area: | 0.20 km2 |
| Basin surface area: | 0.81 km2 |
| Ratio of drainage to lake surface area: | 4.0 |
| Maximum depth: | 35 m |
| Average depth: | 11.4 m |
| Lake volume: | 2.29 x 106 m3 |
| Shoreline development: (Ratio of shoreline distance to the circumference of circle with the same surface area) |
1.36 |
| Trophic status: | meso-oligotrophic |
Castle Lake lies within a low lying basin that collects the runoff and groundwater and incorporates that water into the lake. As such, lakes are affected by features of the basin they are in. The part of the basin filled by water is called the lake basin. The shape of the lake basin affects its volume, area, depth, and the extent of different habitats, as well as the formation of currents and the thermocline. The type of bedrock, surrounding vegetation, and soils in the basin affect the amount and type of nutrients that reach the lake. The granite rocks around Castle Lake have little nutrients in terms of Nitrogen and Phospherous. Most of the Nitrogen that enters the lake is from the leaves of nearby alder trees and other vegetation. Phospherous also comes from terrestrial runoff, as phospherous is binded into the soil.
While there is interannual variation, Castle Lake enjoys four distinct seasons of the year. The influence of the climate on the processes occuring at Castle Lake is great. Please consult the references at the bottom of this page for further study.
In the fall and spring, "overturns" occur which equalize the temperature of the water in the lake. This mixing of the water temperatures brings up essential nutrients that accumulate at the bottom of the lake. This often initiates "blooms" of phytoplankton which stimulate productivity in the whole lake.
Castle Lake. During the summer, a phenomenon known as thermal stratification occurs in lakes. Sunlight heats the top of the lake, forming a layer of warm water over a cooler zone. These warm and cold zones are separated by a zone of mixed water where there is a sharp decline in temperature. Summertime swimmers often experience these temperature layers as their feet hit the sudden cool waters.
Castle Lake frozen in the early spring. With the onset of winter and continuous nights of 0° C temperatures, Castle Lake begins to freeze. Unlike other liquids which are heavier at 0° C, water is heaviest at 4° C. Therefore the bottom of the lake contains water at 4° C while colder water is layered above. This prevents Castle Lake from freezing all the way to the bottom and allows life to remain in the lake throughout the winter. When the ice is solid on Castle Lake, there are also opportunities for great ice skating or ice fishing.
This is the zone in the lake where temperature changes most rapidly with depth. Since solar heating from above is typically the dominant heat source, lakes gain heat from their surface layers. If a temperate lake is deep enough, the deeper waters never warm up and stay at a consistant 4° C (water is most dense at 4° C) all year round. Castle Lake is such a lake.
During the winter the lake is covered with ice, which begins to melt in spring. Once the weather warms up and the sun begins to warm the surface layers, the entire lake becomes the same temperature at 4° C. When heating gets more intense, the warmer surface layers (less dense) float on top of the colder more dense layers. By late summer the surface waters reach 25° C, but at 10 M deep the water is only 10° C. The thermocline varies between 5 and 7 M deep during the summer. Having such a strong temperature (and density) gradient prevents water layers of different density to mix. In other words, the thermocline traps the lighter, warmer water on top of the heavier, colder water. Strong wind waves can shift the depth and gradient of the thermocline, but the main thermocline remains until fall. When sunlight decreases and the air gets colder, surface waters begin to cool and sink. This eventually destroys the thermocline and the lake mixes from bottom-up to reach a constant 4° C. Further cooling forms ice on the lake, which floats during winter. Lake mixing is critical for algal growth because nutrients vital to algae tend to sink to the deeper layers. Nutrients are mostly trapped in the deep layers during summer, while maximum solar energy, also vital for algae, is at the surface. This causes algae to be nutrient limited until the lake mixes and nutrients previously trapped in deep waters are delivered to the surface. The combination of adequate nutrients and sunlight make the algae bloom during this mixing events.
Historically, limnology has focused primarily on the open water or Pelagic portion of lakes. However, the bottom or benthic region of lakes is also bustling with life. Recently, new emphasis has been placed on the study of benthic organisms and the way they interact with and affect the rest of the aquatic ecosystem.
The term benthic invertebrate encompasses a large group of organisms. At Castle Lake this group includes crayfish, bottom dwelling zooplankton, chironimid larvae, and the aquatic larval phase of insects such as caddis flies, stone flies, dragon flies and damsel flies.
In the spring the midge fly makes up a large part of the insect population in Castle Lake. Their main source of food is algae. In the larval stage the midge fly burrows in the silt at the bottom of the lake where it is often found by the fish. As the midge matures it floats to the surface, where it is vulnerable to fish predation. Once the adult midge fly is free of the larval case it flies away to reproduce.
Odonata
Dragonflies
Damselflies
Trichoptera
Caddisflies (Oecetis inconspicua)
Ephemeroptera
Mayflies - several spp.
Diptera - many spp. in Chironomide
Decapoda
Pacific Crayfish (Pacifastacus leniusculus)
Cladocera (Alona guttata)
Mollusca
Pill Clam (Psidium sp.)
Cnidaria
Green Hydra
Porifera
Green Sponge
The osprey, feeding entirely on fish, can often be seen in the spring and summer around Castle Lake. This beautiful hawk nests on the top of dead trees near lakes and streams. It catches fish by hovering, then plunging talons first into the water, catching its prey, then flying back to its nest to feed its young.
Osprey (Pandion haliaetus)
Bald Eagle (Haliaectus leucoephalus)
Golden Eagle (Aquila chrysaetos)
Turkey Vulture (Cathartes aura)
Peregrine Falcon (Falco peregrinus)
Kestrel (Falco sparverius)
Merlin (Falco columbarius)
Wood Duck (Aix sponsa)
Belted Kingfisher (Megaceryle alcyon)
Brown Creeper (Certhia familiaris)
Steller's Jay (Cyanocitta stellere)
Blue Grouse (Dendragapus obscurus)
Castle Lake contains three types of fish--the Golden Shiner, the Brook Char (Brook Trout), and the Rainbow Trout. The Golden Shiner is a minnow that was introduced into the lake by anglers who were using them as bait and left their remaining bait in the lake. The Brook Char was originally stocked by the Department of Fish and Game and now reproduces naturally in the springs on the east side of the lake. The Rainbow Trout is stocked annually by the Department of Fish and Game for sport fishing.
The Golden Shiners and other young fish spend the daylight hours in the shallow areas of the lake among logs and other obstructions hiding from the larger predatory fish and birds. In the evening these fish move into the open lake to feed on zooplankton.
During the spring Rainbow Trout and Brook Char feed mainly on insects like the Midge Fly. In the summer when the surface temperatures are too warm for these trout, they go deeper to feed mainly on zooplankton.
This explains why anglers are usually more successful during the spring and fall when surface temperatures are lower than in the summer. The most successful fishing strategy during the summer is trolling 15 to 20 feet deep where the lake is cooler.
Rainbow Trout (Oncorhynchus mykiss)
Brook Char (Salvelinus fontinalis)
Golden Shiner (Notemigonus crysoliecas)
Algae needs more than sunlight to grow. The mountain alders on the southeast side of Castle Lake help to provide the algae with the essential nutrient nitrogen for their growth. All species of alder have the unique ability to convert nitrogen from the atmosphere into the soil. From the soil, the nitrogen is then filtered into the water which feeds the algae.
Ponderosa Pine (Pinus ponderosa)
Red Fir (Abies Magnifica)
White Fir (Abies Concolor)
Lodgepole Pine (Pinus Contorda)
Incense Cedar (Libocedrus decurrens)
Alder
Green Manzanita (Arctostaphylos patula)
Dwarf Mountain Manzanita (Arctostaphylos neuadensis)
Tan Oak (Lithocarpus densiflorus)
Pitcher Plants (Darlingtonia californica)
Wood Rose (Rosa gymnocarpa)
Shasta Lupine (Lupinus albicaulis)
Red/Crimson/Scarlet Columbine (Aquilegia truncata)
Tiger Lily (Lilium pardalinum)
Pine-drops (Pterospora andromedae)
Douglas Spiraea (Spiraea douglasii)
Scarlet Paintbrush (Castilleja pinetorum)
Alpine Paintbrush (Castilleja arachnoidea)
Dwarf Paintbrush (Castilleja miniata)
Alpine Saxifrage (Saxifraga nidifica)
Shasta Pentstemons (Pentstemon laetus)
Alpine Buckwheat (Eriogonum pyrolaefolium)
Tofield's Swamp Lily (Tofieldia occidentalis)
Black Bear (Ursus americanus)
Mountain Lion (Felis concolor)
Blacktail Deer (Odocoileus hemionus)
Bobcat (Lynx rufus)
Pine Marten (Martes americana)
River Otter (Lutra canadensis)
Western Grey Squirrel (Sciurus griseus)
Chipmonk (Eutamias)
Black-tailed Jackrabbit(Lepus californicus)
Garter Snake (Thamnophis sirtalis)
Rubber Boa (Charina bottae)
Ring-necked Snake (Diadophis punctatus)
Rattlesnake ( Crotalus viridis)
Rough-skin Newt (Taricha granulosa)
Cascade Frog (Rana cascadae)
Zooplankton are the microscopic animals that are adapted to life in the open water. Most zooplankton are about 0.5 to 1 mm in length--just a dot to the human eye, but under a microscope they resemble tiny shrimp, a relative to zooplankton. Some are herbivorous, eating algae, or predaceous, eating other zooplankton.
Daphnia rosea
Holopedium gibberum
Bosmina longirostris
Daphnia middendorfiana
Polyphemus pediculus
Diaptomus novamexicanus
Diaptomus kenai
Tropocyclops prasinus
Macrocyclops albidus
Asplanchna girodi
Collotheca mutablis
Conochilus unicornis
Filinia terminalis
Gastropus stylifer
Synchaeta pectinata
Polyarthra
Keratella
As part of the new UC Davis UNR collaborative research effort at Castle Lake, the Castle Lake Long-term Research Program is being expanded. The primary goals of this expansion are to:
To help flesh out the details, processes and methodologies underlying these goals, in the spirit of this new bi-university collaboration, Dr. Goldman and Dr. Chandra hosted parallel field seminars at their respective institutions during the fall quarter of 2006 focused on food-webs from a landscape perspective (discussion topics and references from these courses are available on the Castle Lake website http://castlelake.ucdavis.edu/). The parallel discussions in the two courses culminated in a joint field trip in early November 2006 where the two groups met, discussed their developing ideas, and joined forces in a whole lake food-web sampling. Dr. Goldman and Dr. Chandra plan to begin implementation of this expanded long-term research effort during the summer 2007 field season.
This is a listing of the available online data for the Castle Lake Long-Term Monitoring station. We will be adding to this list over time.
This is a general query of the available data, for which you can narrow the search by date and parameter.
This query summarizes the data and produces a daily average of the available data, for which you can narrow the search by date and parameter.
This query summarizes the data and produces a daily maximum of the available data, for which you can narrow the search by date and parameter.
This query summarizes the data and produces a daily minimum of the available data, for which you can narrow the search by date and parameter.
One of the most important biological variables monitored in limnological studies is the rate of photosynthetic carbon fixation, known as primary productivity (PPr). The total amount of PPr in a given aquatic system, as well as the ratio of PPr contributions from planktonic algae, aqatic macrophytes (large aquatic plants), and peryphyton (bottom dwelling algae living on rocks and sediment) is interwoven with a whole series of other variables commonly studied by limnologists. During photosynthesis, CO2 is combined with water and light energy from the sun to form the sugars the photosynthetic organism depends upon and releases oxygen as a byproduct:
6 CO2 + 12 H2O (+ sunlight) --> C6H12O6 + 6 O2 + 6 H2O
As such, light penetration, and amount of Dissolved inorganic carbon (DIC) from CO2 all directly affect the reaction. Water temperature is also important as temperature affects reaction speed. As phytoplankton and plants often require other nutrients to survive, levels of chemicals such as Ammonium and Nitrate can also impact the amount of photosynthesis occurring.
Primary Production setup Rate and source of PPr are also closely tied to the structure of the food webs in aquatic systems. Since one of the products of photosynthesis is oxygen, all organisms depending on oxygen for respiration are affected by the amount photosynthesis occurring around them. Oxygen producing planktonic algae and aquatic plants also serve as the food source for many other organisms and the rate at which they are consumed can affect the rate of PPr as well. For example, If the amount of zooplankton increases, their rate of oxygen uptake may increase as may the rate at which they consume phytoplankton. So an increase in the zooplankton community might result in a decrease in PPr. In this way, PPr and resulting amount of oxygen is tied to the food web and may vary as the food web varies in different parts of an aquatic ecosystem.
There are several ways of measuring the rate of PPr commonly used among Limnologists. At Castle Lake, PPr is measured using the 14C method. This technique employs a carbon tracer that gets taken up during photosynthesis along with Carbon available from CO2. Water samples are taken at depths spanning the water column. For each depth there is a dark bottle sample and a light bottle sample (one in which photosynthesis can occur and one in which it cannot). Samples are incubated for a fixed amount of time at the depth they were collected, so that light amount and temperature remains constant for that depth. After incubation, the samples are taken to the laboratory and run through a very fine filter. The rate of photosynthesis at a particular depth can be determined by comparing the amount of tracer on the filter from the light bottle with that of the filter from the dark bottle.
Chlorophyll is the pigment that algal and plant cells use to absorb solar energy in the form of sugars. This process known as photosynthesis, involves chlorophyll, sunlight, water, and CO2. In lakes most of the chlorophyll is associated with phytoplankton and periphyton. Since chlorophyll is mostly found algae, this method gives a way to estimate total algal biomass in the lake and its distribution.
We measure chlorophyll at Castle Lake by taking samples from different depths. After zooplankton are filtered out, the samples are filtered again so that all the algal cells (which contain chlorophyll) are collected on a paper filter. The amount of chlorophyll in each sample is measured from their respective filters, giving an accurate estimate of how much chlorophyll there is at each depth. Depending upon the year and climate, chlorophyll concentrations (algal biomass) varies dramatically at different depths. Generally, the concentration changes as the seasons change.
The DIC measurement is used to determine the original 12C concentration so the Primary Productivity Rate (PPr) can be calculated. In order to calculate primary productivity, the researcher needs to know both how much 14C was added and how much 12C is available to the algae. A water sample for each depth is injected into a vacuum test tube of known volume. A small amount of acid is then injected to convert all inorganic carbon into carbon dioxide. Back in the laboratory at UCDavis, carbon dioxide concentration is measured with an infrared detector. The absorbtion of infrared light is proportional to the amount of carbon dioxide present.
There are many possible carbon contaminants, including air, skin, and many other substances in the lab, so one must be careful while doing this analysis.
This is a GIS Layer (Shapefile) of Castle Lake's Bathymetry (depth).
Thanks to Brian Welde of Angling Technologies (http://www.findyourwater.com) who digitized the Bathymetry map for us, based off our static image.
Coordinate System: GCS North America 1983
Datum: NAD 83
Projection: California Teale Albers
Over the history of Castle lake research, several studies have focused on different aspects of the benthos (The benthos encompasses the plant and animal life on and in the bottom rocks and sediments). Recently, however, the Castle Lake Long Term Research initiative has added regular sampling of large insect larvae or benthic macroinvertebrates in an effort to gain a better understanding of where they fit into the food chain and the role that they play in foraging patterns of fish.
The secchi disk is a white plastic disk that is used to measure the water clarity. The disk is slowly lowered by a marked rope until it is no longer visible, and the depth is noted. Then it is slowly raised until it is visible again. The secchi depth is the average of the two observations.
Secchi disks are widely used because they are durable, transportable, require no power, and--when used consistently--provide a useful measurement of water clarity. The secchi was first used extensively by the Italian astronomer and Jesuit Priest Peitro Angelo Secchi in 1865. It has been used since to measure the transparency of lakes and oceans around the world.
Castle Lake's Secchi depth varies seasonally and inter-annually with an average of 10 M. The world's record Secchi depth is 80 M, observed off Antarctica in October 1986.
The pyroheliometer measures the amount of solar radiation illuminating the earth or, Castle Lake. It is set up next to the lake and the measurements are used in conjunction with other data to calculate the rate and amount of photosynthesis. It also provides a measure of solar heating experienced by the lake, useful in understanding the hydrodynamics of the lake.
It is a relatively simple instrument that records the changes in light
through the expansion and contraction of absorbing black and reflecting silver
metal bands. The expansion and contraction drive a pen on a recording drum.
All the Castle Lake nutrient analyses involve mixing water samples with various chemicals. These chemicals react with the nutrients, forming a colored solution. The nutrient concentration is proportional to the intensity of the solution's color. A spectrophotometer is used to measure the concentration of the colored compound by measuring the light that it absorbs.
At Castle Lake, we conduct the analysis for Nitrate (NO3), Soluable Reactive Phosphorus (SRP), and Ammonia (NH4). Our lab back at UCDavis perform the analyses for Total Phosphorus (TP), and Disolved Inorganic Carbon (DIC).
While Castle Lake has been collecting temperature data for a very long time, more recently it has started to collect water temperature continuously at various depths, providing a temperature profile for the lake. A chain, with loggers as various points, is suspended in the lake, and every five minutes (fifteen minutes during the winter months) a value is collected and stored in the logger.
The movie below, created by Dr. Ted Swift, shows the change in temperature over time at various depths up to 14 meters.
On July 23, 2003, a storm blew in over Castle Lake, and the wind changed the temperature profile of the lake dramatically. The storm hits around the 25 second mark!
A Van Dorn is a water collection device that is used to collect samples for primary production, water chemistry, and ciliate and rotifer analysis. Plugs are pulled against the tube housing by an elastic rubber tube and then held open by loops of metal cable attached to a trigger mechanism. Once triggered, the plugs snap back into place, sealing the tube and capturing the water from that depth. Van Dorns come in various sizes, capturing different volumes. The Van Dorn is used as a primary collection device, immediately to be poured into secondary containers that return to the lab for the various analyses.
A Schindler Trap consists of a clear box with hinged top and bottom. Water flows through as it decends and the top and bottom close as it reaches the desired depth and drawn upward. This prevents further water from entering or leaving and retains a sample of known volume.
Schindler Traps are mainly used to sample for zooplankton collection, as the volume enables the researcher to count the number of zooplankton per unit volume. The enclosure is made of clear material to minimize the visual effect of agile species.
Zooplankton are tiny crustaceans that live in the lake and feed on algae. Some feed on other zooplankton or tiny ciliates and rotifers. Samples are collected weekly, with with samples taken during the day and the night from the following depths: 0, 3, 5, 10, 15, 20, 25, 30, 32, and a pooled mixed layer (PML), formed from equal amounts from 1, 3, and 5 meters.
A Schindler Trap draws a sample of water from a designated depth, then releases the water to capture the zooplankton. When the samples are counted, the various crestatious species are identified and measured through a microscope. Species of zooplankton observed at Castle Lake include Daphnia, Diaptomus, Holopedium, Bosmina, and others.
The data can be used for several purposes, including a clear profile and density distribution of the various species migration patterns. By measuring their respective sizes, one can calculate their relative biomass, an accurate measure of the lakes phytoplankton growth (tropic level below zooplankton), as well as an indicator of the carrying capacity of lakes fish (the tropic level above).
The Castle Lake Limnology Lab has started a new study on bacteria, which is part of a California wide study focusing on the linkage between pathological agents and increased human activity in high elevation lakes. Since Castle Lake is experiencing increased human use this study would enable a comparison with similar lakes and the impact of humans and animals at Castle Lake.
Bacteria sampling began at Castle Lake at five different sites, with the goal of capturing various habitat and human activity. Samples are put in vacuum test tubes and taken to an incubator (held at 35 degrees C). Incubation allows strains of potentially harmful bacteria to be counted, if present, including Escherichia coli and Salmonella. They are in the family Enterobacteriaceae that spends a majority of their lives as residents of animal hosts.
So far, the search has not found anything abnormal.
This project is made possible by Dr. Robert W. Derlet of the UCDavis Medical Center.
This website was built entirely using Open Source software. I would like to acknowledge the Open Source community for providing such great applications and tools!
Castle Lake Limnology
Department of Environmental Science and Policy
University of California at Davis
One Shields Avenue
Davis, CA 95616
Phone: (530) 752-3938
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Help students learn Limnology! Help summer crews at Castle Lake gain valuable field experience; help maintain the Castle Lake lab for summer research and monitoring. Help perpetuate research at Castle Lake and the 45+ year dataset. Your help is very much needed!
Please consider making a monitary contribution to the project. Castle Lake has been vital to the study of limnology and over 40 Ph.D. and Master's theses, and has been the topic of numerous articles, reports, conference proceedings, and posters.
Your contribution is tax-deductable; you are funding education, research, and science, for the students of tomorrow.
Make checks payable to: Friends of Castle Lake
And sent it to:
Castle Lake Limnology
Department of Environmental Science and Policy
University of California at Davis
One Shields Avenue
Davis, CA 95616
Thank you for your support!
Castle Lake is located in the Shasta National Forest of northern California, about 8 miles southwest of Mt. Shasta City (41.13' N, 122.22' W).
From I-5 southbound, drive to Mt. Shasta City and take the Central Mt. Shasta exit. Turn right.
The lab is located about 0.25 mile down the trail. You can't miss it.
If you cross the outflow of the lake, you are going in the opposite direction.
The creation of this website has been an ongoing collaborative effort by many people. We would like to thanks those who have made contributions.
Cigdem Alemdar: phytoplankton and zooplankton photos
Jacquelyn Brownstein: photos
Jim Elser: original hypercard stacks where some content in the foodweb section was used
Brooke Eustis: geological GIS maps, photos
Annie French: photos
Ali Ger: original drafts in foodweb and research sections, photos
Crissy Gilbert: photos
René Henery: original draft in the foodweb and research sections, Castle Lake Newsletter, photos
George Malyj: point of contact, photos
Erich Marzolf: original hypercard stacks where some content in the foodweb section was used
Erik Runquist: photos
Ted Swift: website editing, photos
Dave Waetjen: website administration, original drafts in the foodweb, geography, and research sections, news additions, photos